In existing Third Generation Partnership Project (3GPP) evolved packet core (EPC) networks, mobility management is provided by default in a packet data network (PDN) connection using a general packet radio service (GPRS) tunneling protocol (GTP) tunnel. Otherwise, the traffic is offloaded to bypass the mobile core network. These two choices are not enough to meet the needs of different applications.
In particular, applications have diverse needs of mobility management. Some applications do not need session continuity, and some applications need session continuity. In addition, the quality of service (QoS) requirements on mobility are also diverse in current and emerging applications. In 5G Wireless, the handover delay tolerances for stringent applications are on the order of 10 milliseconds (ms), 1 ms or even sub-ms, whereas those for less stringent applications can be on the order 100 ms, 1 second or even 10 seconds.
These diverse requirements are difficult to meet using a one-size-fits-all solution. For example, a mobility solution for applications with the most relaxed requirements can be much simpler and involve less signaling cost. Using a tight tolerance application mobility solution for all applications can be an overkill and too expensive for the less stringent applications.
Multiple mobility management mechanisms are available currently and more may become available in the future. Examples include the following: application-layer mobility support, transport layer mobility support such as multipath transmission control protocol (TCP), host-based Internet protocol (IP) mobility support such as host-based mobile IP (MIPv6), network-based IP mobility support such as proxy mobile IPv6 (PMIPv6), link-layer mobility support, and the like. It is then necessary to determine whether or not to provide mobility support, and, if so, choose the appropriate mobility support for a given application.